Maxim Integrated MAX809REXR+T Microprocessor Reset Circuit

The Maxim Integrated MAX809REXR+T is a compact, highly reliable microprocessor (µP) supervisory circuit designed to monitor power supplies in digital systems. It provides a significant level of protection to your system by ensuring that the µP and its peripherals are reset properly during power-up, power-down, or brown-out conditions. This component is essential for maintaining the integrity of system logic when the supply voltage becomes unstable or falls below a predetermined threshold.

The MAX809REXR+T comes in a small 3-pin SOT-23 package, making it an ideal choice for space-constrained applications. It is designed to assert a reset signal whenever the VCC supply voltage declines below the factory-set reset threshold level. The reset output remains asserted for a period of at least 140ms after VCC has risen above the reset threshold, providing ample time for the system to stabilize before the processor begins operation. This feature ensures that the system microprocessor starts up in a known state every time.

One of the key features of this supervisory circuit is its precision factory-set VCC reset threshold, which guarantees accurate monitoring without the need for external components. It also offers a low supply current of only 17µA (typical), which is beneficial for battery-operated devices where power conservation is critical.

With its ability to operate over a wide temperature range of -40°C to +85°C, the MAX809REXR+T is versatile and suitable for use in various challenging environments. Its robust design also includes the ability to ignore short transients on the VCC, which helps to prevent false resets from being triggered by noise and fluctuations in the supply voltage.

Overall, the Maxim Integrated MAX809REXR+T is an indispensable component for system designers who require a simple yet effective solution for ensuring the proper operation of their digital systems under all power conditions. Its ease of integration, coupled with Maxim's reputation for quality and reliability, makes it a preferred choice for a wide array of applications, including computers, controllers, intelligent instruments, and portable/battery-powered equipment.